Ingot mold for effervescent steel



E. GLAESENER INGOT MOLD FOR EFFERVESCENT STEEL May 30, 1967 2 Sheets-Sheet 1 Filed April 1, 1965 Ernesf Glaesener INVENTOR.

Attorney I y 1967 E. GLAESEN ER 3,322,390

INGOT MOLD FOR EFFERVE'SCENT STEEL Filed April 1, 1965 Milli ((1% X Fig.3

Ernesf Glasener INVENTOR.

Attorn y 2 Sheets-Sheet 2 United States Patent 45, 0 12 Claims. (Cl. 249-174 My present invention relates to an ingot mold for effervescent steel,

In the pouring of steel ingots it is known to use deoxidizing admixtures, such as aluminum, to produce a so-called calmed or killed steel which is characterized by a substantially homogeneous structure but has a rather irregular surface due to extensive scaling. In contradistinction thereto, steel of the so-called effervescent type (poured without any deoxidizing agent) has a smooth and clean surface but contains a large concentration of impurities in the upper portion of the ingot so that a considerable part of the top of the ingot must be scrapped if a body of good-quality steel is required.

For the purpose of controlling the temperature of the hardening process with steels of the latter type, and of reducing the extent of the cavity or piping developing near the surface of the ingot, it is known to use so-called hot tops which float on the mass and retard its cooling. The positioning of these hot tops in the mold, after the pouring of the hot steel mass, is a difiicult procedure; as an alternative, likewise designed to control the rate of cooling, it is known to use so-called bottleneck molds having a restricted top portion integral with the mold shell proper. The interior of these bottleneck molds, however, is not readily accessible so that the preparatory treatment of the inner m-ol'd surface to prevent spattering, as by the application thereto of a coating of carbon or silicabased substances, is quite inconvenient.

The general object of this invention is to provide an improved ingot mold which obviates the aforestated disadvantages and enables the pouring of effervescent steel in a controlled manner, thus without excessive piping and with a substantially homogeneous structure, so as to combine the advantages of both effervescent and calmed steels with avoidance of their respective drawbacks.

Another object of this invention is to provide an ingot mold adapted to be selectively used for effervescent steel, thus with controlled cooling, or for calmed steel, thus with an open top.

In accordance with this invention I provide a mold Whose upwardly open shell is overlain by a removable lid having at least one inlet opening for the pouring of the molten steel mass; after the pouring, this opening is closed by a suitable plug to provide a substantially complete seal for the open mouth of the shell. The lid may be held in position on the rim of the mold under its own weight and/ or with the aid of releasable fastening means. Advantageously, a depending portion of the lid fits with small clearance inside the top of the mold shell which for this purpose, in the case of an upwardly converging mold, may be internally chamfered along a narrow annular zone at the shell mouth to form a vertical inner surface confronting, with a small all-around clearance of not more than a few millimeters, a vertical peripheral surface of the inserted lid portion. The underside of this lid portion is preferably concave, e.g. frustoconically recessed, to provide a space for the supernatant slag and for evolving gases. The small annular gap surrounding the inserted lid portion may be sealed off by a suitable annular shield, e.g. a strip of sheet metal, and additional sealing means may be provided in the form of an annular 3,322,390 Patented May 30, 1967 gasket disposed between the rim of the shell and an overlying peripheral fiange of the lid. The mold shell, or at least its upper portion, and/ or the lid, at at least its lower portion, are preferably made of heat-insulating refractory material or are lined with such material.

The invention will be described hereafter in greater detail, reference being made to the accompanying drawing in which:

FIG. 1 is a top plan view of a mold provided with a removable lid according to the invention;

FIG. 2 is a cross-sectional view taken on the line II II of FIG. 1; and

FIG. 3 is a view similar to FIG. 2, of the big end up the invention.

The mold 10 illustrated in FIGS. 1 and 2 comprises an upwardly converging shell 11 of refractory and heatinsulating material, such as fire clay, overlain by a removable lid 12 having a horizontal flange portion 13 and a depending central portion 14. The rim of the upwardly and downwardly open shell 11 is formed with lugs traversed by bolts 16 for releasably fastening the lid 12 to the shell. This lid is centrally provided with an opening 17 giving access to the interior of the mold when the lid is in its illustrated position of closure whereby molten steel may be poured into the shell. After pouring, the opening 17 is closed by a plug 18. A frustoconical recess 19 on the underside of lid portion 14 converges upwardly toward the opening 17 and communicates with that opening at the narrow base of its frustocone,

The sloping inner surface of shell 11 is chamfered at 20 so as to extend vertically around a confronting vertical surface 21 of lid 12. The annular gap between these two surfaces 20, 21 may be one or several millimeters wide and is shown sealed at the bottom by a shield 22 attached to lid portion 14; this clearance facilitates the mounting and the removal of the lid, taking into account possible dimensional changes due to variations in temperature. The shield 22 prevents the rise of molten steel into the gap. An annular gasket 23 in the underside of flange 13 sealingly engages the rim of shell '11. Handles 24 enable convenient lifting of the lid 12 by hand or with the aid of overhead transporters.

The modified mold shown in FIG. 3 is generally similar to the mold 10 of FIGS. 1 and 2 and has an upwardly diverging open-ended shell 111 capped by a lid 112 which can be removed for stripping and conditioning. The underside of the central lid portion 114 forms a concavity 119 communicating with an inlet opening 117 in which a plug 118 is removably seated. Lid 112 may be cast, for example, from hematitic iron so as to be sufficiently heavy to rest on the rim of shell 111 under its own weight; a refractory liner extends, however, along its surface 119.

The removable lid 12 or 112, having one or more inlet openings 17 (FIG. 2) or 117 (FIG. 3) adapted to be sealed by plugs 18 or 118, can be conveniently fitted to its shell at an assembly station before the mold is brought to the casting stage. Upon removal of the lid, the shell may be used as a mold for calmed steel or even, if desired, for effervescent steel with use of conventional hot top,

The gasket 23 of FIG. 2 or 123 of FIG. 3 may consist of a refractory material such as asbestos. Similar refractory inserts could be provided in the gap between the lid and the shell, in addition to or in lieu of the seal 22 or 122.

Naturally, my invention may be modified in various aspects without departing from the spirit and scope of the appended claims.

I claim:

1. An ingot mold for effervescent steel, comprising an illustrating a mold type provided with a lid according to upwardly open shell; a lid removably overlying said shell, said lid being provided with at least one inlet opening for the pouring of a molten steel mass; and plug means for closing said inlet opening.

2. A mold as defined in claim 1, further comprising fastening means releasably securing said lid to the top of said shell.

3. A mold as defined in claim 1 wherein said lid has a flange overlying the rim of said shell in a depending portion fitting with small clearance in the open top of said shell.

4. A mold as defined in claim 3, further comprising shield means near the top of said shell for sealing said clearance against the interior of the shell.

5. A mold as defined in claim 3 wherein said depending portion has a concave underside.

6. A mold as defined in claim 5 wherein said underside is formed with a substantially frustoconical recess converging upwardly and communicating with said opening at the narrow base of the frustocone.

7. A mold as defined in claim 3 wherein said flange is provided at its underside with gasket means sealingly overlying the top of said shell.

8. An ingot mold for effervesvent steel, comprising an upwardly converging shell terminating at its top in an open month, said shell having a rim with a vertical inner surface; a lid removably overlying the rim of said shell, said lid having a depending portion with a vertical peripheral surface received in said open mouth with small all-around clearance from said inner surface, said lid having at least one inlet opening traversing said depending portion for the pouring of a molten steel mass into said shell; and plug means for closing said opening.

9. A mold as defined in claim 8 wherein said lid is provided with handle means facilitating its removal from said shell.

10. A mold as defined in claim 8, further comprising fastening means releasably securing said lid to said rim.

11. A mold as defined in claim 8 wherein said rim is internally provided with shield means sealing said clearance against the interior of said shell.

12. A mold as defined in claim 8 wherein at least the lower part of said lid and the upper part of said shell consist of refractory and heat-insulating material.

References Cited UNITED STATES PATENTS 961,854 6/1910 Gathmann 249-474 X 2,190,116 2/1940 Gathmann 2220O X 2,190,393 2/ 1940 Belding 22200 2,264,446 12/ 1941 Marburg 22-20O FOREIGN PATENTS 12,546 9/1914 Great Britain.

J. SPENCER OVERHOLSER, Primary Examiner.

J. HOWARD FLINT, JR., Examiner. 

1. AN INGOT MOLD FOR EFFERVESCENT STEEL, COMPRISING AN UPWARDLY OPEN SHELL; A LID REMOVABLY OVERLYING SAID SHELL, SAID LID BEING PROVIDED WITH AT LEAST ONE INLET OPENING FOR THE POURING OF A MOLTEN STEEL MASS; AND PLUG MEANS FOR CLOSING SAID INLET OPENING. 